title: Anti-GM1 ganglioside IgM-antibodies present in human plasma: affinity and biological activity changes in a patient with neuropathy.
abstract: Low affinity anti-GM1 IgM-antibodies are part of the normal repertoire of human plasma antibodies (Mizutamari et al.: J Neuroimmunol 50:215-220, 1994), a fact that is against the pathological role proposed for them in autoimmune diseases. Here we present evidence that these low affinity IgM-antibodies are devoid of complement-mediated lytic activity to GM1-liposomes, suggesting that they should not be considered harmful. In contrast to the absence in normal individuals, in the plasma of a patient with sensory polyneuropathy we detected high affinity anti-GM1 IgM-antibodies. Concomitant with the presence of these high affinity anti-GM1 IgM-antibodies, the patient plasma is capable of producing complement-mediated lysis of GM1-liposomes. These results suggest that an increase in the affinity of the naturally existing anti-GM1 antibodies could be the trigger that switches them from non-harmful to pathological.
authors.affiliation: Departamento de Química Biológia, Dr. Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba and CIQUIBIC, CONICET, Argentina.
authors.forename: R K
authors.initials: RK
authors.lastname: Mitzutamari
authors.forename: L J
authors.initials: LJ
authors.lastname: Kremer
authors.forename: E A
authors.initials: EA
authors.lastname: Basile
authors.forename: G A
authors.initials: GA
authors.lastname: Nores
mesh_terms: D000328:Adult; D002846:Chromatography, Affinity; D002855:Chromatography, Thin Layer; D003165:Complement System Proteins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005677:G(M1) Ganglioside / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood* / Q000276:immunology; D008081:Liposomes; D010523:Peripheral Nervous System Diseases / Q000097:blood / Q000276:immunology*
chemical_list: D007075:Immunoglobulin M; D008081:Liposomes; D005677:G(M1) Ganglioside; D003165:Complement System Proteins